Like some others have said, it depends on the toilet bowl shape as well as the water height. On most toilets I don't have a problem, but on some I do hit the bowl and/or the water. When that happens, not only does the head of my (circumcised) dick get a good dosing of whatever bacteria are thriving in/on the toilet bowl, but I also get a good shock of the cold water or porcelain--talk about an eye-opener. And if you're in a large public washroom, you can't go and wash your dick off in the sink, having to settle for a TP wipe down. In one of the toilets in the office where I used to work, I could sit down without dipping into the water, but whenever someone else would flush their toilet in the women's bathroom next door, my dick would be hit with a tsunami; I learned to just hold my cock up, just in case. This is pretty high on my list of things I don't like about having a large cock.